Seating bullets with a long ogive

[Apex Predator]

I have been trying to work up a long range hunting load for my 6.5x55 and these Berger VLDs are giving me fits. I used my time tested 140gr load that has worked like magic every time and the long bullets would not group any better then 1.5" (very bad for this gun) I loaded them up to the Sweeds max 3.150 and the results were equaly disappointing. Tried measuring the length to the lands and it was a shocking 3.226" with the vld. Now I have gone a hair over max length before but never anything like this. My magazine will swing it since it is designed for 30-06 length, but is it safe to go that far beyond specs? Could it raise my chamber pressure if I still have a little jump on the lands or would it lower it since I made more room in the case seating the bullet that far out?

 

[ericbc7]

Oal of cartridge is not relevant to safety if your particular rifle will accommodate it. More important (if all cartridge case issues are cool) is if the bullet "jams" into the lands of the chamber. If your load was developed with a bullet seating depth that allows a "jump" to the lands, the pressures of the same load with bullet seated to "jam" will be higher. Look at the riflemans journal for detailed info on how to seat bullets.
http://riflemansjournal.blogspot.com/p/articles-index.html
you will also have to look at the neck tension of the vld bullets but usually the Over all length is the limiting factor.

 

[Andrew Leigh]

I used my time tested 140gr load that has worked like magic every time and the long bullets would not group any better then 1.5" (very bad for this gun) I loaded them up to the Sweeds max 3.150 and the results were equaly disappointing.

Firstly what is your tried and tested load. Powder, bullet, speed COL?

What rifle is it?

Tried measuring the length to the lands and it was a shocking 3.226" with the vld.

Nothing shocking there, if an old 6.5mm they were designed to shoot up to 160gr. bullets so you may well not get the VLD close.

Secondly you do NOT have to be close to the lands with every load. Many rifles have shot excellently well off the lands. I have a .375 that gets me sub 0.7MOA (an once .26MOA) and is .250" off the lands. My mate has a 9.3mm with close to the same jump and he shoots 0.5MOA. I load Sierra's in my 30-06 and am 0.100" off the lands. My 6.5mm on the other hand shoots 140gr. Sierra's from 0.070" of the lands better than 130gr. Accubond's from 0.025" off the lands. Different bullets have different ogives like different jumps, Berger has a nice online article on this. In my experience the more obtuse the ogive the longer the jump

Now I have gone a hair over max length before but never anything like this. My magazine will swing it since it is designed for 30-06 length, but is it safe to go that far beyond specs? Could it raise my chamber pressure if I still have a little jump on the lands or would it lower it since I made more room in the case seating the bullet that far out?

You can go over max but you must ensure that you have at least the diameter of the bullet seated in the case neck else you inevitably will experience run out problems. The internal ballistics are complicated, as you seat out of the case you increase the internal case volume reducing pressure (in the case) the quid pro quo to that is that as you approach the lands you also increase pressure as your require more inertia to get the bullet going. It is NOT equal and opposite so it is a problem to account for.

You may not be able to get close to the lands with your VLD's due to the seating depth in the neck. The other think that I have noticed is that not all 140gr. bullets are equal, they have different ogives, different bearing areas, differing coefficients of friction and they therefore react differently.

This is NOT a load but purely a comparision between bullets using the same powder, COL etc. as calculated by QuickLOAD ballistic software.

140gr. Berger 2 711fps (at max pressure)
140gr. SGK 2 664fps
140gr. Accubond 2 704fps
140gr. Speer 2 653fps

The above variances are sufficient to take you off an accuracy node. Bothe the Bergers and the Accubonds are sleeker resulting in increased velocity due to decreased obtuseness of the ogive.

Do you possess a chrony?

 

[steve4102]

Tried measuring the length to the lands and it was a shocking 3.226" with the vld.
Now I have gone a hair over max length before but never anything like this. My magazine will swing it since it is designed for 30-06 length,
but is it safe to go that far beyond specs? Could it raise my chamber pressure if I still have a little jump on the lands or would it lower it since I made more room in the case seating the bullet that far out?

It is important to understand that the SAAMI OAL specs are for ammunition and rifle manufactures, so that every factory round will fit in every factory chamber.

These "spec" have nothing to do with the handloader, he/she is free to adjust OAL to whatever works for them and their rifle.

Yes, increasing OAL will raise pressures.

If you are going to increase your OAL up close to the lands you should drop your charge down a little and work it back up.

Here is an article from Berger on their VLD and OAL.

http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/

Here is one from Accurate Shooter.

http://bulletin.accurateshooter.com/2009/03/berger-tips-for-loading-vld-bullets/

 

[Apex Predator]

First off my go to load is 46.5 gr RL22 with a oal of 3.095 (2.995" with my sierras) this load has given me consistant 1/4 to 1/2 MOA with every 140 I have tried until the VLD. It clocks right around 2700fps. I use mostly PPU brasd and CCI 200 primers.
I know I don't have to be jammed into the lands to get accuracy but the super long ogive is the only thing I can think of that is screwing me up, so seating the bullet well over max oal seems to be the only solution.
I ran out of RL22 a couple weeks ago so I am going to gave to play around with the load some anyway since nobody has any. Thinking about giving H1000, H4831, RL19 or AA3100 a try.

 

[steve4102]

Your Max for that bullet is,

Tried measuring the length to the lands and it was a shocking 3.226" with the vld.

Anything over 3.226 is "over max" anything under 3.226 is "Less than Max".

Forget SAAMI max, it has no place on your reloading bench.

 

[243winxb]

OK to jump VLD Berger http://www.bergerbullets.com/information/ Here is a better link, copied from Berger http://www.thehighroad.org/showpost.php?p=9171474&postcount=7